block: Consolidate command flag and queue limit checks for merges

[mirror_ubuntu-zesty-kernel.git] / block / blk-merge.c

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 86710ca408b862d38f1876c59332ff3753033ec4..642b862608a1b246196a26773efc257f7c9d5673 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -275,14 +275,8 @@ no_merge:
 int ll_back_merge_fn(struct request_queue *q, struct request *req,
                     struct bio *bio)
 {
-       unsigned short max_sectors;
-
-       if (unlikely(req->cmd_type == REQ_TYPE_BLOCK_PC))
-               max_sectors = queue_max_hw_sectors(q);
-       else
-               max_sectors = queue_max_sectors(q);
-
-       if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
+       if (blk_rq_sectors(req) + bio_sectors(bio) >
+           blk_rq_get_max_sectors(req)) {
                req->cmd_flags |= REQ_NOMERGE;
                if (req == q->last_merge)
                        q->last_merge = NULL;
@@ -299,15 +293,8 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
 int ll_front_merge_fn(struct request_queue *q, struct request *req,
                      struct bio *bio)
 {
-       unsigned short max_sectors;
-
-       if (unlikely(req->cmd_type == REQ_TYPE_BLOCK_PC))
-               max_sectors = queue_max_hw_sectors(q);
-       else
-               max_sectors = queue_max_sectors(q);
-
-
-       if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
+       if (blk_rq_sectors(req) + bio_sectors(bio) >
+           blk_rq_get_max_sectors(req)) {
                req->cmd_flags |= REQ_NOMERGE;
                if (req == q->last_merge)
                        q->last_merge = NULL;
@@ -338,7 +325,8 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
        /*
         * Will it become too large?
         */
-       if ((blk_rq_sectors(req) + blk_rq_sectors(next)) > queue_max_sectors(q))
+       if ((blk_rq_sectors(req) + blk_rq_sectors(next)) >
+           blk_rq_get_max_sectors(req))
                return 0;
 
        total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
@@ -417,6 +405,9 @@ static int attempt_merge(struct request_queue *q, struct request *req,
        if (!rq_mergeable(req) || !rq_mergeable(next))
                return 0;
 
+       if (!blk_check_merge_flags(req->cmd_flags, next->cmd_flags))
+               return 0;
+
        /*
         * not contiguous
         */
@@ -512,6 +503,9 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
        if (!rq_mergeable(rq) || !bio_mergeable(bio))
                return false;
 
+       if (!blk_check_merge_flags(rq->cmd_flags, bio->bi_rw))
+               return false;
+
        /* different data direction or already started, don't merge */
        if (bio_data_dir(bio) != rq_data_dir(rq))
                return false;